US 4,857,666 AGranted

Alkylation/transalkylation process

AssigneeUop LLC

InventorsPaul T. Barger, Gregory J. Thompson, Raymond R. Herber, Tamotsu Imai

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Abstract

An alkylation-transalkylation process for the production of a monoalkylated aromatic compound is disclosed which maximizes the production of desirable monoalkylaromatic compounds, while limiting transalkylation catalyst deactivation. The process entails the combination of an alkylation reaction zone, a first seperation zone, a second separation zone, and a transalkylation reaction zone wherein the alkylation catalyst and transalkylation catalyst are dissimilar and where the alkylation catalyst is comprised of phosphoric acid material and the transalkylation catalyst is comprised of a crystalline aluminosilicate material. The transalkylation catalyst deactivation is reduced by transalkylating only dialkylated aromatic compounds. Additionally, the transalkylation catalyst is regenerable utilizing a hot liquid hydrocarbon wash.

Claims13

Dependent claims

A process for the production of alkylated aromatics and containing a regenerable transalkylation catalyst which comprises the steps of:

(a) passing a feedstream comprising an alkylating agent and an aromatic substrate to an alkylation reaction zone and into contact with a solid phosphoric acid containing catalyst under conditions providing for the liquid phase alkylation of said aromatic substrate;
(b) separating in a first separation zone the product from the alkylation reaction zone and a hereinafter described transalkylation reaction zone product into fractions comprising (1) an aromatic substrate fraction, (2) a substantially pure monoalkylated aromatic fraction, and (3) a fraction comprising compounds with boiling points higher than the desired monoalkylated aromatic;
(c) separating in a second separation zone the fraction comprising compounds with boiling points higher than the desired monoalkylated aromatic of the first separation zone into a dialkylated aromatic-rich fraction, and into fractions with higher and lower boiling points than the dialkylated aromatic-rich fraction;
(d) passing a feed stream of an aromatic substrate and the separated dialkylated aromatic-rich hydrocarbon fraction of the second separation zone to a transalkylation reaction zone containing crystalline aluminosilicate catalyst under conditions providing for the transalkylation of said dialkylated aromatic-rich hydrocarbon fraction to produce a transalkylation reaction zone product;
(e) introducing the transalkylation reaction zone product from step (d) into the separation zone of step (b);
(f) recovering the monoalkylaromatic fraction;
and
(g) intermittently halting the flow of the separated dialkylated aromatic-rich hydrocarbon fraction of the second separation zone to the transalkylation reaction step (d) and thereby allowing only the aromatic substrate to contact and regenerate the crystalline aluminosilicate transalkylation catalyst until essentially no catalyst deactivating material remains on the catalyst and thereafter resuming the flow of the separated dialkylated aromatic-rich hydrocarbon fraction to the transalkylation reaction step.

5 more elements

A process containing a regenerable transalkylation catalyst useful in the liquid phase production of a monoalkylbenzene which comprises the steps of:

(a) reacting a C.sub.2 -C.sub.14 monoolefin alkylating agent with benzene in the presence of a solid phosphoric acid containing alkylation catalyst under conditions providing for the liquid phase alkylation of said benzene;
(b) separating in a first separation zone said alkylation reaction zone effluent stream, a transalkylation reaction zone effluent stream as hereinafter characterized, and a benzene containing feed stream into (1) a benzene-rich feed fraction, (2) a substantially pure monoalkylbenzene product fraction, and (3) a fraction rich in compounds with boiling points higher than the desired monoalkylbenzene;
(c) separating in a second separation zone the fraction rich in compounds with boiling points higher than the desired monoalkylbenzene of the first separation zone into a dialkylbenzene-rich fraction, and into fractions with higher and lower boiling points than the dialkylbenzene-rich fraction;
(d) transalkylating the dialkylbenzene-rich fraction with a first portion of the separated benzene-rich feed fraction in the presence of a transalkylation reaction zone catalyst comprising an inorganic oxide-bound crystalline aluminosilicate material in a transalkylation reaction zone under transalkylation reaction conditions to produce a transalkylation reaction zone effluent stream;
(e) supplying the effluent of the transalkylation reaction zone to said first separation zone as said transalkylation reaction zone effluent stream;
(f) passing a second portion of said unreacted benzene-rich feed fraction to said alkylation reaction zone as a portion of the alkylation reaction zone feed;
(g) recovering said monoalkylbenzene product fraction from the separation zone;
and
(h) regenerating the transalkylation catalyst when the transalkylation catalyst dialkylaromatic conversion performance is at least 10 percent below that of the fresh transalkylation catalyst dialkylaromatic conversion performance by:
(i) directing the flow of the separated dialkylated aromatic-rich hydrocarbon fraction to storage or to the alkylation reaction zone,
(ii) contacting the transalkylation catalyst with the separated benzene-rich feed fraction of step (d) at a temperature of at least 100.degree. C. until essentially no catalyst deactivating material remains on the transalkylation catalyst;
and
(iii) resuming the flow of the separated dialkylated aromatic-rich hydrocarbon fraction of the second separation zone to the transalkylation reaction zone under transalkylation reaction conditions.

10 more elements

A process containing a regenerable transalkylation catalyst useful in the liquid phase production of cumene which comprises the steps of:

(a) reacting propylene with benzene in the presence of a solid phosphoric acid containing alkylation catalyst in an alkylation reaction zone operating at a temperature of from 100.degree.-390.degree. C., a pressure of from 1-130 atmospheres, a liquid hourly space velocity of from 0.5 to 50 hr.sup.-1, and a benzene to propylene molar feed ratio of from 1:1 to 20:1;
(b) passing the alkylation reaction zone effluent stream, the transalkylation reaction zone effluent stream as hereinafter characterized, and a benzene containing feed stream into a first separation zone wherein entering hydrocarbons are separated into an unreacted benzene-rich feed fraction, a substantially pure cumene and product fraction, and a fraction rich in compounds with boiling points higher than cumene;
(c) separating in a second separation zone the fraction rich in compounds with boiling points higher than cumene of the first fractionation zone into a diisopropylbenzene-rich fraction and into fractions with boiling points higher and lower than that of the dipropylbenzene-rich fraction;
(c) transalkylating the diisopropylbenzene fraction with a first portion of the separated benzene-rich feed fraction in the presence of a transalkylation reaction zone catalyst comprising from 5% to 95% by weight of mordenite, from 5% to 95% by weight of Al.sub.2 O.sub.3, at a transalkylation reaction zone temperature of from 100.degree. C. to 390.degree. C., a pressure of from 1 to 130 atmospheres, a liquid hourly space velocity of from 0.1 to 50 hr-1 and a benzene to diisopropylbenzene molar feed ratio of from 1:1 to 1:20 to produce a transalkylation reaction zone effluent stream;
(e) supplying the effluent stream of the transalkylation reaction zone to said first separation zone as said transalkylation reaction zone effluent stream;
(f) passing a second portion of said unreacted benzene-rich feed fraction to said alkylation reaction zone as a portion of the alkylation reaction zone feed;
(g) recovering said cumene product fraction from the separation zone;
and
(h) regenerating the transalkylation catalyst when the diisopropylbenzene conversion across the transalkylation catalyst is at least 25 percent below that of the fresh catalyst diisopropylbenzene conversion performance by:
(i) directing the flow of the diisopropylbenzene-rich fraction of the second separation zone to the inlet of the alkylation reaction zone;
(ii) contacting the transalkylation catalyst with the first portion of the separated benzene-rich fraction in the liquid phase and at a temperature of at least 250.degree. C. until essentially no catalyst reactivating material remains on the transalkylation catalyst;
and
(iii) directing the flow of the diisopropylbenzene-rich fraction of the second separation zone to the transalkylation reaction zone.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/247,810Filed 21 Sep 1988 · continuation in part
Priority: 11 Sep 1987
Granted: 15 Aug 1989
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

C07C 6/126
Of exclusively hydrocarbons containing a six-membered aromatic ring: of more than one hydrocarbon
C07C 2/70
Catalytic processes: with acids
C07C 15/02
Cyclic hydrocarbons containing only six-membered aromatic rings as cyclic parts: monocyclic hydrocarbons
C07C 2527/173
Phosphates or other compounds comprising the anion -: phosphoric acid or other acids with the formula Hn+2PnO3n+1